[Deoxyribonuclease from Corynebacterium diphtheriae: dynamics of synthesis and properties]

Diphtheritic bacteria of PW-8 Massachusetts strain produced into cultural medium only one nucleotidase--endoDNAase. The enzyme was synthesized by the cells during the exponential phase of growth. The DNAase was purified 500-fold and exhibited properties specific to neutral-alkaline DNAases (pH optimum about 7.5, absolute requirements for Me2+, single-step mechanism of substrate hydrolysis). The following properties were typical for the enzyme: absence of distinct specificity to structure of bases surrounding the hydrolyzed bond, formation of 5'-end phosphate groups and slightly higher preference to denatured DNA.